This CURB-65 calculator scores pneumonia severity from five bedside items — Confusion, Urea, Respiratory rate, Blood pressure, age 65 — and returns the published 30-day mortality and the care setting that score usually maps to.






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Five Letters That Triage Pneumonia

The sore-throat end of respiratory scoring is our Centor Score Calculator. Part of our Health Calculators collection.

Worked Example

  • 70-year-old, RR 32, confused, urea normal, BP fine: age (1) + RR (1) + confusion (1) = score 3 → ≈ 17% 30-day mortality — hospital, with higher-level-care assessment on the table
  • The bands move management, not just prognosis: 0–1 home territory, 2 crosses the admission line, 3+ opens the ICU conversation, 4–5 makes it urgent
  • Urea’s unit trap: the criterion is > 7 mmol/L in SI units ≈ BUN > 19–20 mg/dL in US units — the same patient, two lab dialects (the US BUN is urea × 2.8, a conversion that has genuinely confused real charts)

Score Discipline

  • Confusion means NEW disorientation (AMT ≤ 8 or known-baseline change) — chronic cognitive impairment without acute change is a classic false point.
  • CRB-65 drops urea for community use (score 0 → home consideration; ≥ 1 → hospital assessment) — know which version a pathway cites.
  • Oxygen saturation isn’t in CURB-65, yet hypoxemic patients escalate regardless — the score and the oximeter are both consulted, neither vetoes the other.
  • PSI (Pneumonia Severity Index) is the finer-grained alternative; CURB-65 wins on speed and memorability at the bedside.

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Frequently Asked Questions

How is CURB-65 calculated?

One point each for: Confusion, Urea > 7 mmol/L (BUN > ~19–20 mg/dL), Respiratory rate ≥ 30, Blood pressure low (systolic < 90 or diastolic ≤ 60), and age ≥ 65 — total 0–5. This calculator totals them and reports the classic published mortality and usual care setting per score.

What is the mortality for each CURB-65 score?

From the Lim 2003 derivation cohort (30-day mortality): 0 → 0.7%, 1 → 3.2%, 2 → 13%, 3 → 17%, 4 → 41.5%, 5 → 57%. These are the figures BTS/NICE guidance reproduces; modern cohorts with earlier antibiotics may read somewhat lower.

What score means hospital admission?

Conventionally: 0–1 home (1 with support/short stay considered), 2 hospital admission, 3 admission plus assessment for higher-level care, 4–5 urgent critical-care assessment. Clinical judgment, oxygen needs and social factors can move any individual patient up a level.

What is the difference between CURB-65 and CRB-65?

CRB-65 omits the Urea point (no lab needed), making it the primary-care/community version: 0 = home treatment possible, 1–2 = hospital assessment, 3–4 = urgent admission. CURB-65 proper needs the blood urea and is used where labs are available.

Does CURB-65 apply to all pneumonias?

It was derived in adults with community-acquired pneumonia. It underperforms in the very elderly (where age alone saturates it), in nursing-home and hospital-acquired pneumonia, and it doesn’t capture oxygenation — hence its role as a decision aid alongside, not instead of, assessment.

Is this CURB-65 calculator medical advice?

No — an educational implementation of a published score. Pneumonia with breathlessness, confusion or low oxygen needs urgent in-person care.